ウキクサー根　微生物共生系を利用したフエノ　ルの　化促

摘要

For the confirmation of the accelerated phenol degradation effect and understanding itsmechanisms in the rhizosphere of aquatic plant Spirodela polyrrhiza, phenol degradation tests andmicrobial monitoring were performed using pond water with/without Spirodela or sterilized Spirodela.Phenol degradation was accelerated in pond water with Spirodela and even with sterilized Spirodela incomparison to pond water. During phenol degradation, the number of 16S rDNA, and catechol1,2-dioxygenase (C120) and catechol 2,3-dioxygenase (C230) genes on Spirodela rhizoplane and in pondwater was monitored by MPN-PCR as indicators of total bacteria and phenol degrading bacteria,respectively. It revealed that Spirodela selectively accumulated and supported the growth of bacteriapossessing C120 and C230 genes on the rhizoplane. Thus Spirodela acts as a "stimulator" of phenoldegrading bacteria in its rhizosphere to accelerate phenol degradation in pond water.